A high gain soft-switching active-clamped coupled-inductor-based converter for grid-tied photovoltaic applications

Due to increased demand for electricity and to curtail large consumption of fossil fuels, researchers are more focused on renewable energy sources, particularly solar photovoltaic (PV). In general, grid-tied PV systems require a high voltage boosting stage, leading to reduced efficiency. A converter is proposed along with the high gain and soft-switching capabilities by using an active-clamped circuit to the coupled inductor for grid-tied PV system applications. In this circuit, high gain is achieved by incorporating switched capacitors (SCs) in conjunction with the coupled inductor and regenerative diodes. The SCs are connected in such a way that, they store the energy in parallel and deliver the energy in a series. By using the active-clamped circuit, the switching overvoltages are diminished and also improvement in converter efficiency with the zero-voltage switching (ZVS). The operating principle of the converter and its design procedure is presented. Finally, to validate the theoretical analysis, the obtained experimental results from a laboratory prototype of 500 W rated at 100 kHz with the variation of input voltage, 36–48 V, and output voltage 400 V are presented.